Apollo 15 launched on July 26, 1971 with three astronauts, James Irwin, David Scott and Alfred Worden, who all had ties to the University of Michigan. For several reasons, the mission is considered one of NASA's most challenging for their crews. For one, it was the longest stay on the lunar surface of all the Apollo missions. It also was the first mission to use a lunar rover, which itself has a Michigan connection as the vehicle was, in-part, manufactured by General Motors.

But the myth that stemmed from this mission is one that to this day, still has a loyal following. According to an article published years ago by Michigan Daily, the astronauts took the opportunity to represent the University of Michigan on the moon by placing a "block M" flag on the lunar surface before they came home. But a retired aerospace engineering professor says he can debunk this myth.

Harm Buning, who knows the Apollo 15 astronauts personally, says rumors of an extraterrestrial block M flag being only one of two along with the U.S. flag are misguided.

Buning said he thinks the rumor started because of the 20 miniature Michigan flags that accompanied the astronauts as they broke the bounds of Earth but never left the spacecraft. Upon their return to Earth, some of the flags were given to the aerospace engineering department. Buning keeps one at his Ann Arbor home. None of the flags ever made it to the lunar surface.

The rumor was passed down through the years at the university. It showed up in the planner distributed to freshmen and was even a staple of Campus Day tours. Many still maintain that there actually is a Michigan flag on the moon.

But even if there isn't a flag there, U of M is represented in a a different way on the lunar surface. The astronauts left a document on the Moon establishing a lunar branch of the University's alumni association.

It reads:

"The Alumni Association of The University of Michigan. Charter Number One. This is to certify that The University of Michigan Club of The Moon is a duly constituted unit of the Alumni Association and entitled to all the rights and privileges under the Association's Constitution."